In panel display devices, thin film transistor liquid crystal displays (abbreviated as TFT-LCDs) have characteristics of small volume, low power consumption, relatively low manufacturing cost and no radiation, and thus prevail in the current market of planar panel displays. Liquid crystal displays are more and more widely used in modern life. A liquid crystal display can be commonly used as a display screen for cell phone, a display screen for Note Book, a display screen for GPS or a display screen for liquid crystal television. With the development of science and technology, traditional displays for displaying planar images only cannot meet people's demand for the display quality. Three Dimension (abbreviated as 3D) displays, which have been widely studied in recent years, display images in a three dimensional manner so that the images are not limited to the plane of the screen, thereby the picture is more vivid and makes the viewer have an immersive feeling. 3D display devices are mainly classified into two types, i.e., glasses-wearing type and naked-eye type. 3D display devices of the glasses-wearing type require the viewer to wear a pair of particular 3D glasses, otherwise the images which are seen by the viewer on the 3D display devices are fuzzy images.
3D display devices of naked-eye type are convenient to use without wearing glasses and thus have been widely used. 3D display devices of naked-eye type can be classified into barrier fence type naked-eye 3D display devices and lens type naked-eye 3D display devices. Both types can achieve the switching between 2D mode and 3D mode by controlling whether a voltage is applied to the liquid crystal electrode and can ensure the left and right eyes of the human to respectively receive a correct image by controlling the magnitude of the voltage. The barrier fence type naked-eye 3D display device has been widely studied, because its manufacturing process is compatible with the process of a planar display screen such as a liquid crystal display screen or an organic light emitting screen. The barrier fence type 3D display device achieves 3D displaying through superposing a layer of Twisted Nematic (abbreviated as TN) type liquid crystal grating on the surface of the display panel on the light emitting side. Such three dimension display process is inexpensive and is developed well, and can achieve the switching between 2D mode and 3D mode. However, in the common barrier fence type 3D display device, the layer of liquid crystal grating superposed on the display panel usually has a thickness of about several ten millimeters, thereby the module is a relatively thick as a whole, while at the time of 2D display mode, light needs to pass through the liquid crystal layer and thus the light transmittance is low and the display effect is poor.